Nanoparticle enhanced coupled bioheat vapor bubble model and simulation for LITT in breast tumors

Laser-Induced Thermotherapy (LITT) efficacy hinges on achieving localized heating and controlled vaporization within tumor tissue. Building upon our previously developed fully-coupled bioheat vapor bubble model, this study integrates gold nanoparticles (GNPs) to enhance optical absorption and bubble dynamics during LITT of breast tumors. Gold nanoparticles (spherical, ~ 60 nm diameter) were considered to enhance optical absorption and bubble dynamics. We introduce an additional heat-source term, [Formula: see text], to the Pennes bio heat equation, where [Formula: see text] ​and [Formula: see text] denote the nanoparticle absorption coefficient and concentration. Latent-heat effects and Rayleigh Plesset bubble dynamics are retained from the baseline model. Simulations were carried out for fluences of 30-80 J/cm² using an 800 nm near-infrared (NIR) Gaussian laser beam, applied as a 50 ms square pulse .Through simulations comparing nanoparticle rich ([Formula: see text] particles/mL) and nanoparticle free scenarios across laser fluences of [Formula: see text], our results show that GNPs reduce vaporization threshold fluence by approximately 20%, increase peak temperature by ~ 15 [Formula: see text] and elevate peak bubble radius from ~ 12 μm to ~ 18 μm. Sensitivity analyses reveal significant dependencies of necrotic zone size on nanoparticle parameters. This nanoparticle-enhanced model offers a powerful theoretical framework for optimizing LITT protocols, potentially reducing required laser doses and minimizing collateral damage.